The present invention is related to an X-ray radiation detector, X-ray imaging apparatus, X-ray CT apparatus and a method of manufacturing the X-ray detector, and more specifically to the X-ray radiation detector having a plurality of detector cells arrayed in combination of scintillator with a photoelectric transducer element such as a photodiode, various devices and apparatuses incorporating the detector, and the method of manufacturing the detector.
As a detector as have been described above, for example, there are known detectors, which are used for X-ray CT apparatuses. These detectors may have a plurality of detector cells arranged in the direction of channels. There are also known detectors, called multiple arrayed detectors, which may additionally have detector cells arranged in the direction perpendicular to the channel direction (row direction).
FIG. 8 shows a schematic cross sectional view of the detector of the prior art in either the channel direction or row direction. The detector 500 contains a plurality of detector cells 501, each detector cell 501 may have a scintillator 502 and a photodiode 503. Each scintillator 502 is isolated from neighbors scintillators with a reflector 504, which reflects lights, in order to prevent the light that has been transformed from X-ray beam from being received by the photodiode 503 in an adjacent detector cell 501, in other words to avoid the crosstalk. In addition, provided on each of the reflectors 504 is a collimator 505, which limits the X-ray radiation incident into the scintillator 502 to improve the detection precision. It should be noted here that the collimator 505 is provided in order to compensate for the precision error caused by the manufacturing process of the scintillator 502, for example, for the purpose of equalize the surface area of incident plane of each detector cell or the distance between two adjoining incident planes, and is formed thicker than the reflector 504 in the array direction (horizontal direction in the drawing) of each detector cell 501.
As can be seen from the foregoing, in the prior art detector, a predetermined rate of surface area of the X-ray incident plane is occupied by the reflector 504 and the collimator 505, part of incident X-ray attained to the incident plane may not be converted to light, thus not be detected by the scintillator 502. This means that the acquisition efficiency of X-ray is decreased. The loss of X-ray in the channel direction and row direction may respectively reach to 20%, depending on the distance between detector cells and the width of collimator 505, as a total the X-ray loss of 40% may be seen.
As a technology which resolves such problem as have been described above, the technology disclosed in the patent reference 1 is known. The technology disclosed in the patent reference 1 eliminates the reflectors, and arranges a plurality of photodiodes in one collimator to suppress the X-ray losses caused by the collimator and reflector and to improve the resolution.
[Patent Reference 1] JP-A-2004-93489
However, in accordance with the technology disclosed in the patent reference 1, since no reflector is placed, the crosstalk to the adjacent cells will be increased due to the light diffusion, when thickening the scintillator in order to increase the collection efficiency of the incident X-ray.